The devices of the aforementioned kind of the known type, called inappropriately "drawers" in the field, usually comprise a body of the device housing one or more vessels, each containing a quantity of a respective washing agent, such as a detergent, bleach, fabric conditioner or another type, and means for conveying respective flows of water to each of said washing agents housing vessels to remove the agent contained therein and for transporting it to the tub of the machine, where the operation of washing the articles of laundry takes place.
In the "drawers" of the known type said means for conveying the flows of water to the vessels to remove the respective washing agent comprise conveying conduits for respective flows of water, which conduits end with holes formed in a wall of the body of the device situated at said vessels, from which the respective flow of water is poured into corresponding vessels for removing the washing agent contained in the latter.
The use of this kind of device of the known type is disadvantageous from various viewpoints. There is first of all a problem linked to the presence of ions or encrusting agents in the flows of water for removing the washing agents passing through said conduits and holes of the device or "drawer" housing the washing agents. Said flows of water for removal, after a certain period of time of use of the washing machine, therefore have the tendency to leave encrusting deposits which clog the conduits and, more particularly, the holes for transfer of the flow of water to the respective washing agents housing vessels.
This fact, which obviously is felt more greatly in areas wherein the water available has a particularly high degree of hardness, entails, after a certain number of cycles of use of the washing machine, the impossibility of providing any flow of water or a correct flow of water for removing a suitable quantity of detergent. This leads to incomplete washing operations and even those which are damaging to the garments being washed.
In order to avoid these disadvantages, current practice consists in replacing the clogged detergents housing drawer with a new drawer, which operation may only be concluded by specialist staff specially contacted by the domestic user of the washing machine.
This operation is therefore, as well as irritating in that it involves stopping the machine until the specialist technician has answered the call affirmatively, excessively expensive, in that it entails a certain cost inherent in the total cost of the drawer to be replaced and the cost of the work force used during this operation of replacement.